There is simply no way this is actually a good faith attempt to benefit the citizenry here. None.
Just like there is simply no way that you actually post your comments in good faith, right? Because everything that everyone does is always bad, always, right?
You know the saying. When everyone around you is an asshole, you're the asshole.
Of course the cops aren't going to complain when someone so stupid as to walk into their lobby right next to a picture of them and the warrant that's out for their arrest that's posted on the wall makes it easy for them. But the idea here is to simply shut down some scam transactions before they even occur. They don't have to DO anything - just make it clear that people who are uncomfortable with a transaction with stranger are welcome to meet up in the safest place available. Just like they tell you that you any time you think you might be being pulled over by someone who's not a real cop (say, an unmarked car), you can drive to the parking lot of a police station before pulling over. That's been the policy everywhere I've lived for decades.
Your eagerness to make a safe transaction or the serendipitous arrest of a stupid known, predatory criminal a bad thing is truly bizarre. Which of those two things is not in support of "the citizenry?" Which backwards world view are you holding that makes either of those things something nefarious on the part of the local police station? Grow up.